Print carrier and transportable cartridge for the same

ABSTRACT

A print carrier for use in a chain printer apparatus which comprises an endless band with a plurality of printing fingers integrally formed with the band. Each of the printing fingers is provided with a print character. The band includes at least one integrally formed continuous strip portion, clocking means, and guide means. Desirably, the print carrier is utilized in a transportable cartridge assembly, which includes means for insuring proper print character alignment. The print characters can be made of plastic injection molded onto each of the print fingers.

United States Patent [191 Bowers, Jr. et a1.

1 1 PRINT CARRIER AND TRANSPORTABLE CARTRIDGE FOR THE SAME [75]Inventors: George W. Bowers, Jr., Hayward;

Tony W. Broski, Jr., San Jose; John Pastrone, Los Gatos, all of Calif.

[73] Assignee: Memorex Corporation, Santa Clara,

Calif.

22 Filed: Oct. 2, 1972 21 Appl. No.: 294,222

Related U.S. Application Data [62] Division of Ser. No. 21,464, March20, 1970.

[52] U.S. Cl 101/111, 101/93 C, 197/175 [51] Int. Cl B4lj 7/32, B4ljl/2O [58] Field of Search 101/93 C, 111, 382 MV; 197/175, 168, 151;24/230-231, 240-242; 242/197-199 [56] References Cited UNITED STATESPATENTS 3,605,610 9/1971 McDowell et a1 101/93 C 3,381,611 5/1968 Foley101/382 MV X 3,557,693 l/197l Kuchenbecker et al. 101/93 C 3,354,816ll/1967 Gianuzzi 101/93 C Antonucci 101/93 C [451 Apr. 23, 19742,950,048 8/1960 Luhn 101/111 X 3,236,468 2/1966 Foret 242/199 X3,621,968 11/1971 Kondor 197/168 X OTHER PUBLICATIONS E. Kraemer, IBMTechnical Disclosure Bulletin, Vol. 13, No. 11, April 1971, p. 3366. 1

Primary Examiner-Robert E. Pulfrey Assistant Examiner-E. M. CovenAttorney, Agent, or FirmLimbach, Limbach &.

Sutton [57] ABSTRACT A print carrier for use in a chain printerapparatus which comprises an endless band with a plurality of printingfingers integrally formed with the band. Each of the printing fingers isprovided with a print character. The band includes at least oneintegrally formed continuous strip portion, clocking means, and guidemeans. Desirably, the print carrier is utilized in a transportablecartridge assembly, which includes means for insuring proper printcharacter alignment. The print characters can be made of plasticinjection molded onto each of the print fingers.

6 Claims, 9 Drawing Figures KATE-INTER APR 2 3 I974 SHEET 1 1F 4 FIG-.1.

BACKGROUND OF THE INVENTION The present invention relates to a printcarrier, and more particularly to a print carrier for use in a chainprinting apparatus.

Chain printing apparatus has become important in applications requiringhigh speed printout. The general operational principle of chain printingis well-known. A chain or print carrier is rotated about two drums-orspools. Carried on the chain are a plurality of printing fingers whichare each provided with a different print character. Each of the printingfingers will pass past the printing area one time during each revolutionof the chain.

In order to print a character, a hammer assembly is provided within thearea about which the print carrier rotates. As the desired characterpasses the printout area a hammer is actuated. When actuated, the hammerstrikes the desired print finger as it passes by which in turn strikesthe printout paper.

The speed of printing is largely a function of the speed at which theprint carrier can be rotated past the printing area as well as the speedat which the hammers can strike the print fingers.

Prior art print carrier chain belts include those constructed from wovenmetallic links an those from rubber belts. In the latter kind, the printcharacters are placed on pins which are inserted in the edge of therubber belt. Such constructions are inefficient in operation, expensiveto manufacture, and subject to breakage and misalignment at the speedsrequired in many of todays applications.

Prior art print carriers typically are difficult to load and unload whena different set of characters is required. Further, very few constraintshave been placed on the print carrier to insure that the print fingersare properly aligned and positioned at the time when the hammer assemblyis activated to print out the desired character.

SUMMARY OF THE INVENTION According to the present invention a continuousprint carrier is provided which includes a plurality of y print fingerswhich are integrally formed with the remainder of the carrier band orbelt. The band or belt additionally includes at least one continuousstrip extending circumferentially around the band and also includestiming or clocking means which forms a part of the carrier forco-operative use with suitable sensing means in the chain printapparatus in order to properly actuate the hammer assembly to print thedesired character. Desirably, the print fingers are of a bifurcatedconstruction with the print characters secured to the projecting baseportion of the bifurcation.

Additionally, guide means are provided on the print carrier whichcooperate with the chain printing apparatus to insure that the printfingers are properly aligned in a direction parallel with the axis ofrotation of the print carrier. Desirably, the guide means comprises agenerally V-shaped projection extending circumferentially around thecarrier and may be constructed from an extended plastic sheet bonded tothe print carrier or can be formed by crimping a portion of the printcarrier itself.

The print characters can be mounted on each of the plurality of printfingers in a number of ways. For example, the print characters can bemade from metal and spot welded to each of the print fingers. In thepreferred embodiment of the present invention, the print characters aremade from plastic and are injection molded directly onto the printfingers.

In accordance with yet another feature of the present invention theprint carrier band is provided with a' transportable cartridge which isadopted for easy placement within a chain printing apparatus. Thecartridge includes a recess for receiving the hammer assembly of thechain printing apparatus. The cartridge includes a sidewall portionwhich cooperates with the guide means on the print carrier band foraccurately maintaining the print fingers in the desired position at thetime of printing as the print fingers are conveyed past the hammerassembly.

The sidewall additionally includes a magnetic guidance means forpreventing movement of the print fingers in a radial direction relativeto the rotation of the print carrier as the print fingers pass thehammer assembly.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of atypewriter embodying aspects of the present invention.

FIG. 2 is a cross-sectional view of FIG. 1 along section lines 2-2.

FIG. 3 is a perspective view of a print carrier band in accordance withthe present invention.

FIG. 4 is an enlarged view of a portion of the print carrier band shownin FIG. 3.

FIG. 5 is a cross-sectional view of the print carrier of FIG. 4 shownalong the direction indicated by the arrows.

FIG. 6 is a perspective view of another embodiment of the print carriershown in FIG. 3.

FIG. 7 is a perspective view of an improved print carrier cartridgesuitable for use in a chain printing apparatus.

FIG. 8 is a cross-sectional view of the cartridge shown in FIG. 7 in adirection indicated by the arrows.

FIG. 9 is a cross-sectional view of the spool mounting assembly takenalong the direction indicated by the arrows in FIG. 7.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A general understanding of thechain printing appa-' ratus using the improved print carrier andcartridge of the present invention will be facilitated by reference nowto FIG. 1 and 2. FIG. 2 is a cross-section of FIG. I along section lines2--2. For greater clarity, the sprocket drive for computer type paper isnot shown in FIG. 1. The typewriter or other chain printing apparatus isshown on a standard 1 and includes many conventional features includinga case 2, a keyboard 4, a cylindrical platen 6 having control knobs 8 ateach end, retractable bar and paper guide rollers 10, fixed paper guiderollers 11, and levers 12 for adjusting to paper thickness and forselecting the number of spaces between lines. Lever 14 controls therelease of rollers 16 and 18 and the release of platen 6 in order forpaper to Two possible paper feeds are shown in FIG. 2. A conventionalfeed is accomplished by inserting a piece of paper 24 between the rearof platen 6 and retractable rollers 16 and 18. As lever 14 is pulledpartially forward, rollers 16 and 18 retract thus facilitatinginsertion. A second feed, for computer paper is made at opening 26 atthe bottom rear of case 2. Paper guides 28 and 30'guide the computerpaper 32 along a curved path upward to the platen 6. To permit easyinsertion of the computer paper, lever 14 is pulled forward to itsextreme position thus moving the entire platen assembly 36 (shown inFIG. 4) to the rear slightly away from vertical spring guide 34. Asprocket drive assembly 38 is employed when using computer paper in thetypewriter unit. Details of these two paper feeds are the subject of anapplication of Ingemar H. Lundquist and John Pastrone filed concurrentlyherewith.

There is shown in FIG. 3 an improved print carrier chain or belt 101which is illustrative of the present invention. The belt is rotatedabout two spools (not shown) located. at opposite ends of the belt. Thebelt is continuous and includes a plurality of print fingers 103 whichhave included thereon the desired print characters. Located alongthe'bottom of the belt 101 is a clocking means comprising a plurality ofperferations or holes 105.

In operation, the belt 101 rotates around spool or drums placed atopposite ends of the print carrier 101 in the direction indicated by thearrow. The exact position of each of the print fingers 103 are easilysensed by any suitable sensing means (not shown) such as a.

photo or magnetic detector. This information is used to monitor theposition of the passing printing fingers and to activate the hammers 25at the proper time. Thus as the desired print finger 103 passes thehammers 25, the hammer assembly is actuated and a hammer 25 strikes theappropriate print finger 103 to print out the desired character.

A generally V-shaped ridge 109 is provided circumferentially around theprint carrier 101. The ridge 109 is utilized in a manner which will bedescribed in more detail subsequently to guide the print fingers 103past the hammers 25.

Details of the print carrier belt 101 are shown in FIGS. 4 and 5. Theprint fingers 103 are bifurcated and include a base portion 111 and apair of legs 113. The ends of the legs 113 are integrally formed with astrip 115 which includes the plurality of timing holes 105. Strip 115additionally includes a C-shaped hole 117 which acts as the home orreference hole for purposes of monitoring the print fingers 103.

A. continuous strip 119 extends circumferentially around the entireprint carrier 101. As may be seen, the continuous strip 119 isintegrally formed with the bifurcated print fingers 103 the legs ofwhich it bisects.

The print carrier 101 can be formed from a single piece of thin materialsuch as stainless steel. It has been found that 410 stainless steelwhich is magnetic and weldable, and which is approximately 0.005 inchesthick works well. The configuration shown in FIG. 3 is desirably formedby use of well-known photo-chemical techniques. However the inventionshould not be limited thereto since the configuration of FIG. 4 couldalso be formed by mechanical stamping operations. An endless band isformed by lap-welding or otherwise securing the ends of the bandtogether.

To the base portions 111 of the print fingers 103 are attached thedesired print characters 121. In the preferred embodiment of the presentinvention the print characters are made from plastic. The print fingers103 are placed within a mold having the configuration of the desiredcharacter. Plastic such as a polycarbonate is injected within the moldto form the characters 121. Alternately, the characters may be made frommetal and spot welded to the print fingers 103.

A guide means formed by the generally V-shaped ridge 109 is best seen byreference to FIG. 5. In the embodiment illustrated in FIGS. 4 and 5, theridge 109 is made from a material such as polyurethane which is bothtransparent and flexible. The polyurethane rubber is extruded into athin bandwhich additionally includes generally flat portions 123 and125. To secure the extruded ridge 109 and flat portions 123 and 125 tothe print carrier 101, a second piece of similar plastic material 127(FIG. 5) is opposite thereto with the finger portions 1 13 of the printfingers 103 sandwiched therebetween. The two pieces of plastic arebonded together.

The ridge 109 can be used in conjunction with suitably disposedreceiving means provided as a part of the chain print apparatus. Furtherdetails of this aspect of the present invention will be describedsubsequently.

FIG. 6 is illustrative of an alternate means by which the guide means orridge 109 may be formed. Rather than using extruded plastic bands, theridge 109 is formed by crimping the leg portions 113 of the printfingers 103. The legs 113 are crimped into a V-shape suitable for use inguiding the print carrier belt 101. Where practical, other means may beused for guiding the carrier and preventing its movement axially withrespect to drive pulleys, but the V-shaped ridge 109 is preferred.

The transportable cartridge 20 shown in FIG. 1 is illustrated in greaterdetail in FIGS. 7 and 8. The cartridge 20 includes a housing 132 whichforms a recess 134 for receiving a hammer assembly 136 illustrated inphantom in FIG. 8. The hammer assembly 136 includes the hammer 25 forstriking the print fingers 103 as required. Details of a hammer assemblymay be seen by reference to the patent application of Ronald T. Albo andJohn Pastrone filed concurrently herewith, and assigned to the assigneeof the present invention.

The belt 101 rotates within the housing 132 about two spools or drums138 shown in FIG. 9. The spools 138 are mounted within the housing 132in an improved manner and will be described subsequently in thedescription of FIG. 9.

The housing 132 includes a sidewall 140 which includes a recessedportion 142 which cooperates with the V-shaped guide means or ridge 109of the print carrier 101 as it passes the hammer assembly 136. As aresult of this guiding system, the print characters 121 are constrainedfrom moving in a direction parallel with the axis of rotation of therespective spools, e.g., referring to FIG. 8, in an upward or downwarddirection.

It is also important that the print characters 121 be maintained in apath which is a proper distance from the hammer 25. If the printcharacter 121 is too close to the hammer 25 the print finger 103 canscrape across the surface of the print-out paper which can result indamage thereto.

To remedy this problem, an improved magnetic guidance means 146 isprovided. Magnetic guidance means 146 includes a strip of magneticmaterial 148 such as rubber impregnated with magnetized particles whichis secured to the sidewall 140 in the vicinity of the hammers 25. Themagnetic material is embedded within the sidewall 140 by a (-shapedmetal holder 150. In order to prevent damage to the passing printfingers 103, the exposed surface of the magnetic material 148 and theends of the (-shaped channel 150 are coated with a suitable bearingsurface such as Teflon. Thus, as the print fingers 103 pass by themagnetic means 146, the print fingers are drawn to the magnetic material148 and yet remain undamaged due to the Teflon surface provided thereon.The magnetic guide 146 is particularly effective in holding the printcharacter fingers in line as they come around the pulleys at high speedwhere contrifugal force tends to pull them out of line. This magneticguide means 146 is very useful in permitting high speed operation of thechain whether the chain is mounted in the carriage or directly in thecase 2 with the magnetic guide 146 also mounted in the case.

When the cartridge 130 is placed within the chain printing apparatus,the print drive shaft 150 acts against the biasing action of the spring158 to lift off the spool 138 from the seat portion 154. In thisposition, the spool 138 is free to rotate about the bearing 162.

Such a cartridge arrangement gives the chain printing apparatus greatflexibility in that different sets of character print can be exchangedeasily and conveniently in a very quick and simple operation. Further,as a result of the magnetic guidance means and the guide arrangementused, great accuracy in print out is insured.

We claim:

1. A transportable cartridge assembly adaptable for use with a chainprinter apparatus including a hammer assembly having a print line with aplurality of selectively operable hammers and at least one drive shaftoperably connectable to said cartridge assembly for rotating a printcarrier belt past the print line, said cartridge assembly comprising:

a. an elongated housing assembly;

b. first and second spools including means for rotatably mounting thesame at opposite ends of said housing and wherein at least one of saidspools additionally includes means for engaging the drive shaft of thechain printer apparatus; and

c. an endless print carrier belt having an edge from which a pluralityof printing fingers project, each printing finger having a distal endwith a print character secured thereto, each finger being at least inpart comprised of a ferromagnetic material; said carrier belt beingmounted about said first and second spools for rotation in an oblongmanner around said spools;

wherein said housing assembly encases a substantial portion of the printcarrier belt and includes an inner guiding sidewall arrangedlongitudinally between the spools on the print line, said sidewallhaving an outwardly facing guide surface against which the endless beltand printing fingers are conveyed and having an edge across whichhammers from the hammer assembly selectively strike the distal ends ofsaid printing fingers, which ends project beyond the edge of thesidewall; said sidewall including a magnetic guidance means mounted inthe outwardly facing guide surface adjacent the edge for restrainingmovement of the printing fingers in a general direction radially to thatof the rotating print carrier belt.

2. The transportable cartridge assembly as in claim 1 wherein saidelongated housing assembly includes an elongated substantially centralrecess therein for receiving the hammer assembly of the chain printerapparatus.

3. A cartridge assembly as in claim 1 wherein said magnetic guidancemeans includes a magnetic element covered by a suitable bearing surfacefor slidably engaging the printing fingers as each is conveyedtherepast.

4. A cartridge assembly as in claim 1 wherein said spools include acircumferential surface having a recessed portion extendingcircumferentially around said spools and said outwardly facing guidesurface of said sidewall includes a recessed portion extending along atleast a part of its length, said recessed portions receiving suitableprojecting guide means provided circumferentially around said printcarrier belt for restricting movement of said belt to a circumferentialdirection.

5. A cartridge assembly as in claim 1 wherein said spools aresubstantially cylindrical with a top surface and a bottom surface andwherein at least one of said mounting means comprises a seating surfaceformed in said housing which engages the bottom surface of at least oneof said spools, a bearing means axially engaging the top surface of thespool, and biasing means for maintaining the bottom surface of the spoolin frictional contact with the seating surface and for permitting saidspool to be raised from said seating surface when said spool is engagedby the drive shaft of the chain printer apparatus.

6. A cartridge assembly as in claim 5 wherein said housing includes aspring retaining portion and wherein said biasing means comprises aspring which is loaded within said spring retaining portion and a ballhearing which is seated in said top surface of the spool in engagementwith the spool.

1. A transportable cartridge assembly adaptable for use with a chainprinter apparatus including a hammer assembly having a print line with aplurality of selectively operable hammers and at least one drive shaftoperably connectable to said cartridge assembly for rotating a printcarrier belt past the print line, said cartridge assembly comprising: a.an elongated housing assembly; b. first and second spools includingmeans for rotatably mounting the same at opposite ends of said housingand wherein at least one of said spools additionally includes means forengaging the drive shaft of the chain printer apparatus; and c. anendless print carrier belt having an edge from which a plurality ofprinting fingers project, each printing finger having a distal end witha print character secured thereto, each finger being at least in partcomprised of a ferromagnetic material; said carrier belt being mountedabout said first and second spools for rotation in an oblong manneraround said spools; wherein said housing assembly encases a substantialportion of the print carrier belt and includes an inner guiding sidewallarranged longitudinally between the spools on the print line, saidsidewall having an outwardly facing guide surface against which theendless belt and printing fingers are conveyed and having an edge acrosswhich hammers from the hammer assembly selectively strike the distalends of said printing fingers, which ends project beyond the edge of thesidewall; said sidewall including a magnetic guidance means mounted inthe outwardly facing guide surface adjacent the edge for restrainingmovement of the printing fingers in a general direction radially to thatof the rotating print carrier belt.
 2. The transportable cartridgeassembly as in claim 1 wherein said elongated housing assembly includesan elongated substantially central recess therein for receiving thehammer assembly of the chain printer apparatus.
 3. A cartridge assemblyas in claim 1 wherein said magnetic guidance means includes a magneticelement covered by a suitable bearing surface for slidably engaging theprinting fingers as each is conveyed therepast.
 4. A cartridge assemblyas in claim 1 wherein said spools include a circumferential surfacehaving a recessed portion extending circumferentially around said spoolsand said outwardly facing guide surface of said sidewall includes arecessed portion extending along at least a part of its length, saidrecessed portions receiving suitable projecting guide means providedcircumferentially around said print carrier belt for restrictingmovement of said belt to a circumferential direction.
 5. A cartridgeassembly as in claim 1 wherein said spools are substantially cylindricalwith a top surface and a bottom surface and wherein at least one of saidmounting means comprises a seating surface formed in said housing whichengages the bottom surface of at least one of said spools, a bearingmeans axially engaging the top surface of the spool, and biasing meansfor maintaining the bottom surface of the spool in frictional contactwith the seating surface and for permitting said spool to be raised fromsaid seating surface when said spool is engaged by the drive shaft ofthe chain printer apparatus.
 6. A cartridge assembly as in claim 5wherein said housing includes a spring retaining portion and whereinsaid biasing means comprises a spring which is loaded within said springretaining portion and a ball bearing which is seated in said top surfaceof the spool in engagement with the spool.